Abstract
To improve the geometric efficiency of cardiac SPECT imaging, we have previously proposed to use a ring geometry and a multi-segmental collimation. The proposed collimation consists of multiple parallel collimators with most of the segments focused on a small central region, where the patient heart should be positioned. This scheme provides an significantly increased detection efficiency for the central region, but at the expense of reduced efficiency for the surrounding background. We have used computer simulations to evaluate the implication of this scheme on the accuracy of the reconstructed cardiac images. Two imaging situations were simulated, one with the heart well placed in the center, the other with the heart shifted outward and partially outside the central region; a neighboring high uptake liver was also simulated. The images were reconstructed with ML-EM and OS-EM methods using a complete attenuation map. The results indicate the deviation caused by truncation is not significant and is not strongly dependent on the activity of the liver when the heart is well positioned within the central region. The distribution of activity in the myocardium reconstructed with ML-EM or OS-EM is not sensitive to the noisy projections sampled from the background. When the heart is positioned improperly, the image reconstructed from the hybrid emission (a combination of high-count projections through the central region and low-count background projections) can restore the activity for the myocardium with increased noise variances in the section outside the central region.
Original language | English (US) |
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Pages | 1638-1642 |
Number of pages | 5 |
State | Published - 1996 |
Externally published | Yes |
Event | Proceedings of the 1996 IEEE Nuclear Science Symposium. Part 1 (of 3) - Anaheim, CA, USA Duration: Nov 2 1996 → Nov 9 1996 |
Other
Other | Proceedings of the 1996 IEEE Nuclear Science Symposium. Part 1 (of 3) |
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City | Anaheim, CA, USA |
Period | 11/2/96 → 11/9/96 |
ASJC Scopus subject areas
- Radiation
- Nuclear and High Energy Physics
- Radiology Nuclear Medicine and imaging